Radio frequency (RF) power detector circuits are often employed to measure the power of RF signals. This power measurement has a number of uses, including controlling the output of RF amplifiers in order to increase their efficiency and ensure that they are transmitting RF signals at appropriate amplitudes.
As RF power detectors are used to measure power, a number of characteristics are desirable. For example, one desirable attribute of RF power detectors is linear response within their normal dynamic range, so as to ensure predictability and accuracy of measurement. Another desirable attribute is temperature compensation, as power detectors whose outputs vary with operating temperature are, in general, less predictable. Yet another desirable attribute is directional coupling. More specifically, it is often desirable for RF power detectors to be sensitive only to power delivered by the RF signal source to be monitored, and insensitive to other sources of RF signals, such as reflected signals and ambient noise.
In view of these attributes, continuing efforts exist to improve the various characteristics of RF power detector circuits.